五、spring boot整合mybatis-plus

發布時間：2020-07-11 01:24:29 來源：網絡閱讀：3530 作者：狼興人生欄目：編程語言

spring boot整合mybatis-plus

簡介

mybatis 增強工具包，簡化 CRUD 操作。文檔
http://mp.baomidou.com
http://mybatis.plus

優點 | Advantages

無侵入：Mybatis-Plus 在 Mybatis 的基礎上進行擴展，只做增強不做改變，引入 Mybatis-Plus 不會對您現有的 Mybatis 構架產生任何影響，而且 MP 支持所有 Mybatis 原生的特性
依賴少：僅僅依賴 Mybatis 以及 Mybatis-Spring
損耗小：啟動即會自動注入基本CURD，性能基本無損耗，直接面向對象操作
預防Sql注入：內置Sql注入剝離器，有效預防Sql注入***
通用CRUD操作：內置通用Mapper、通用Service，僅僅通過少量配置即可實現單表大部分 CRUD 操作，更有強大的條件構造器，滿足各類使用需求
多種主鍵策略：支持多達4種主鍵策略（內含分布式唯一ID生成器），可自由配置，完美解決主鍵問題
支持熱加載：Mapper 對應的 XML 支持熱加載，對于簡單的 CRUD 操作，甚至可以無 XML 啟動
支持ActiveRecord：支持 ActiveRecord 形式調用，實體類只需繼承 Model 類即可實現基本 CRUD 操作
支持代碼生成：采用代碼或者 Maven 插件可快速生成 Mapper 、 Model 、 Service 、 Controller 層代碼，支持模板引擎，更有超多自定義配置等您來使用（P.S. 比 Mybatis 官方的 Generator 更加強大！）
支持自定義全局通用操作：支持全局通用方法注入（ Write once, use anywhere ）
支持關鍵詞自動轉義：支持數據庫關鍵詞（order、key......）自動轉義，還可自定義關鍵詞
內置分頁插件：基于Mybatis物理分頁，開發者無需關心具體操作，配置好插件之后，寫分頁等同于寫基本List查詢
內置性能分析插件：可輸出Sql語句以及其執行時間，建議開發測試時啟用該功能，能有效解決慢查詢
內置全局攔截插件：提供全表 delete 、 update 操作智能分析阻斷，預防誤操作

前面已經創建了一個springboot項目，我們直接在該項目上整合mybatis-plus

準備工作

pom.xml jar引入： <mybatis-plus.version>3.0.6</mybatis-plus.version>

 <dependency>
        <groupId>com.baomidou</groupId>
        <artifactId>mybatis-plus-boot-starter</artifactId>
        <version>${mybatis-plus.version}</version>
    </dependency>

    <dependency>
        <groupId>com.baomidou</groupId>
        <artifactId>mybatis-plus</artifactId>
        <version>${mybatis-plus.version}</version>
    </dependency>

創建表

CREATE TABLE `my_info` (
`id` int(10) NOT NULL AUTO_INCREMENT,
`name` varchar(255) DEFAULT NULL,
`age` int(3) DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

項目結構

創建基本的項目結構，controller、dao、entity、service(impl)
如圖：
五、spring boot整合mybatis-plus

controller :

@RestController
public class MyInfoController {
    @Resource
    MyInfoService myInfoService;

    @GetMapping("myInfo")
    public String myInfo(@RequestParam Integer id) {
        MyInfo myInfo = myInfoService.getById(id);
        return myInfo.toString();
    }
}

dao :

public interface MyInfoMapper extends BaseMapper<MyInfo> {

}

entity :

@Data
@TableName(value = "my_info")
public class MyInfo {
    @TableId(type = IdType.AUTO)
    private Integer id;

    private String name;

    private Integer age;
}

service :

public interface MyInfoService {

     MyInfo getById(int id);
}

impl :

@Service("myInfoService")
public class MyInfoServiceImpl extends ServiceImpl<MyInfoMapper,MyInfo> implements MyInfoService {
    @Override
    public MyInfo getById(int id) {
        return baseMapper.selectById(id);
    }
}

當前，我們也可以在xml中自定義sql( MyInfoMapper.xml )

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" >
<mapper namespace="com.honghh.bootfirst.dao.MyInfoMapper">
    <!--自定義SQL-->
</mapper>

application.yml 配置文件內容如下

spring:
  datasource:
    type: com.alibaba.druid.pool.DruidDataSource
    driver-class-name: com.mysql.jdbc.Driver
    url: jdbc:mysql://localhost:3306/boot_demo
    username: root
    password: 123456
#mybatis
mybatis-plus:
  mapper-locations: classpath*:mapper/**/*.xml
  #實體掃描，多個package用逗號或者分號分隔
  typeAliasesPackage: com.honghh.bootfirst.entity
  global-config:
    #主鍵類型  0:"數據庫ID自增", 1:"用戶輸入ID",2:"全局唯一ID (數字類型唯一ID)", 3:"全局唯一ID UUID";
    id-type: 0
    #字段策略 0:"忽略判斷",1:"非 NULL 判斷"),2:"非空判斷"
    field-strategy: 2
    #駝峰下劃線轉換
    db-column-underline: true
    #刷新mapper 調試神器
    refresh-mapper: true
    #數據庫大寫下劃線轉換
    #capital-mode: true
    # Sequence序列接口實現類配置
    #key-generator: com.baomidou.mybatisplus.incrementer.OracleKeyGenerator
    #邏輯刪除配置
    #logic-delete-value: -1
    #logic-not-delete-value: 0
    #自定義填充策略接口實現
    #meta-object-handler: com.baomidou.springboot.xxx
    #自定義SQL注入器
    sql-injector: com.baomidou.mybatisplus.mapper.LogicSqlInjector
  configuration:
    map-underscore-to-camel-case: true
    cache-enabled: false
    call-setters-on-nulls: true

啟動項目

完成上面的步驟，準備工作將近完成，現在開始啟動項目，但是你會發現項目啟動不起來，報錯如下：

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'myInfoController': Injection of resource dependencies failed; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'myInfoService': Unsatisfied dependency expressed through field 'baseMapper'; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'com.honghh.bootfirst.dao.MyInfoMapper' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
    at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.postProcessProperties(CommonAnnotationBeanPostProcessor.java:324) ~[spring-context-5.1.5.RELEASE.jar:5.1.5.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1395) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:592) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:515) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:320) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:318) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:849) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:877) ~[spring-context-5.1.5.RELEASE.jar:5.1.5.RELEASE]
    at org.springframework.context.support.AbstractApplicationContext.__refresh(AbstractApplicationContext.java:549) ~[spring-context-5.1.5.RELEASE.jar:5.1.5.RELEASE]
    at org.springframework.context.support.AbstractApplicationContext.jrLockAndRefresh(AbstractApplicationContext.java:40002) ~[spring-context-5.1.5.RELEASE.jar:5.1.5.RELEASE]
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:41008) ~[spring-context-5.1.5.RELEASE.jar:5.1.5.RELEASE]
    at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:142) ~[spring-boot-2.1.3.RELEASE.jar:2.1.3.RELEASE]
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:775) [spring-boot-2.1.3.RELEASE.jar:2.1.3.RELEASE]
    at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397) [spring-boot-2.1.3.RELEASE.jar:2.1.3.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:316) [spring-boot-2.1.3.RELEASE.jar:2.1.3.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1260) [spring-boot-2.1.3.RELEASE.jar:2.1.3.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1248) [spring-boot-2.1.3.RELEASE.jar:2.1.3.RELEASE]
    at com.honghh.bootfirst.BootFirstApplication.main(BootFirstApplication.java:11) [classes/:na]
Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'myInfoService': Unsatisfied dependency expressed through field 'baseMapper'; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'com.honghh.bootfirst.dao.MyInfoMapper' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:596) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
    at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:90) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessProperties(AutowiredAnnotationBeanPostProcessor.java:374) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1395) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:592) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:515) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:320) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:318) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:204) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.resolveBeanByName(AbstractAutowireCapableBeanFactory.java:452) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
    at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.autowireResource(CommonAnnotationBeanPostProcessor.java:526) ~[spring-context-5.1.5.RELEASE.jar:5.1.5.RELEASE]
    at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.getResource(CommonAnnotationBeanPostProcessor.java:496) ~[spring-context-5.1.5.RELEASE.jar:5.1.5.RELEASE]
    at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor$ResourceElement.getResourceToInject(CommonAnnotationBeanPostProcessor.java:636) ~[spring-context-5.1.5.RELEASE.jar:5.1.5.RELEASE]
    at org.springframework.beans.factory.annotation.InjectionMetadata$InjectedElement.inject(InjectionMetadata.java:180) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
    at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:90) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
    at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.postProcessProperties(CommonAnnotationBeanPostProcessor.java:321) ~[spring-context-5.1.5.RELEASE.jar:5.1.5.RELEASE]
    ... 19 common frames omitted
Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'com.honghh.bootfirst.dao.MyInfoMapper' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.raiseNoMatchingBeanFound(DefaultListableBeanFactory.java:1654) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1213) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1167) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:593) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
    ... 35 common frames omitted

上網查了一下，說一般是下面原因造成的：

1.applicationContext.xml配置中沒有掃描包
2.controller層的@controller或者service層的@Service注解沒寫
3.service注入mapper失敗

仔細看了下代碼是mapper層沒有注入，mapper注入方法有一下幾種方式。

1.直接在mapper上寫注解

@Mapper
public interface MyInfoMapper extends BaseMapper<MyInfo> {

}

2.在啟動類上添加注解

@EnableTransactionManagement
@SpringBootApplication
@MapperScan("com.honghh.*.dao")

public class BootFirstApplication {

    public static void main(String[] args) {
        SpringApplication.run(BootFirstApplication.class, args);
    }

}

mybatis-config中只是會為對應的mapper創建代理類，而想真正包裝成bean，注入到spring容器中，還是需要靠AutoConfiguredMapperScannerRegistrar，它會根據掃描@Mapper注釋或是@MapperScan指定的包下的接口，將其注冊為bean。

3.也可以寫一個配置類 MybatisPlusConfig

@Configuration
@MapperScan(basePackages = "com.honghh.*.dao")
public class MybatisPlusConfig {
    /**
     * mybatis-plus 分頁插件
     */
    @Bean
    public PerformanceInterceptor performanceInterceptor() {
        return new PerformanceInterceptor();
    }
}

在瀏覽器中輸入：http://localhost:8080/myInfo?id=1 顯示如下
五、spring boot整合mybatis-plus
成功！！！此時你已經學會了整合mybatis-plus

參考文本

https://gitee.com/baomidou/mybatisplus-spring-boot

文章來源： https://blog.csdn.net/qq_35098526/article/details/87782961

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五、spring boot整合mybatis-plus

spring boot整合mybatis-plus

簡介

優點 | Advantages

準備工作

項目結構

啟動項目

參考文本

猜你喜歡

91超碰碰碰碰久久久久久综合_超碰av人澡人澡人澡人澡人掠_国产黄大片在线观看画质优化_txt小说免费全本

五、spring boot整合mybatis-plus

spring boot整合mybatis-plus

簡介

優點 | Advantages

準備工作

項目結構

啟動項目

參考文本

猜你喜歡

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